> CPUs run at 60-70C, while the outside ambient is usually 30C or less, so heat should just "flow downhill" with a bit of help from fans, pumps, etc.
This isn't how you think of heat flow. The CPUs run at a given power. Their temperature will depend on the ambient temperature, and on the thermal impedance between them and the ambient. If the thermal impedance is too high, they'll be too hot and die.
This isn't how you think of heat flow. The CPUs run at a given power. Their temperature will depend on the ambient temperature, and on the thermal impedance between them and the ambient. If the thermal impedance is too high, they'll be too hot and die.